The present invention concerns a gripper weaving machine in which the rapier guide includes two series of guide elements for guiding the rapiers in the shed which are presented when the sley is in its backmost position to guide the rapiers on both sides.
It is known that such rapier guides can be made in various embodiments. Traditionally, two series of guide elements are used, preferably in the form of small hooks, which operate in conjunction with the sides of the rapiers, for example as described in patents U.S. Pat. No. 3,299,911, BE 902,913, DE 869,477, FR 1,476,950 and patent applications NL 7607608, FR 2,217,451 and EP 137,376. The use of this type of rapier guide has the disadvantage that the weft threads are easily caught in the guide elements which are situated closests to the reed when the sley is moved forward again. This occurs in particular in weaves where the position of the bottommost warp threads remains unchanged during the insertion of several weft threads.
The use of rapier guides known from the above-mentioned patents also has the disadvantage, at least in the case when the rapier drive is fixed and does not move along with the sley, that the insertion of the rapiers in the shed can only start as soon as the sley and the guide elements fixed to it are in their backward position; additionally, the rapiers must be removed from the shed as soon as the sley is moved forward again. In order to accelerate the weaving process, it is required that the rapiers and the sley can make overlapping movements.
French patent No. 1,467,950 describes a device which partly allows such overlaps. This is due to the fact that the top of the rapier is rounded off so that the rapier makes contact with the rapier guide elements only later, such that these rapier guide elements still have some freedom of movement. This solution has the disadvantage that the overlap remains limited.
It is also known for rapier guides to consist on the one hand of guide hooks which operate in conjunction with that side of the rapier which is turned away from the reed, and on the other hand of a support which is located underneath the bottommost warp threads, for example as described in the Belgian patent No. 900,044, the Dutch patent application No. 7607608 and the European patent application No. 204,274. In this arrangement the rapiers slide over the bottommost warp threads, and therefore this arrangement has the disadvantage that the warp threads with which the rapiers make contact are easily damaged. This arrangement also has the disadvantage that the harness drive must see to it that the bottommost warp threads are in their bottommost position before the rapiers are inserted in the shed. As a result, the overlap of the movement of the harnesses and the rapiers is limited.